textproduct: Rapid City

KEY MESSAGES

-Warm and windy this week with critical to near critical fire weather conditions the rest of the week

-Cooler early next week with some chances for showers

UPDATE

Issued at 1011 PM MDT Wed May 13 2026

Isolated showers and thunderstorms will continue to move across northeast WY and western SD tonight as the surface-low over southern AB continues to move east. Gusty winds (~40-50 mph) are associated with these showers, with little to no precipitation reaching the ground. Expect thunderstorms to continue to weaken throughout the night as they push through western SD. The cold front associated with the low will begin to push into the region early Thursday (~7Z-9Z) and shift winds west/northwesterly. The strongest winds behind the cold front will be over northwest SD, where a Wind Advisory is in effect from 9 AM to 6 PM MDT for west winds of 25 to 35 mph, with gusts up to 55 mph. Thursday will bring temperatures in the 80s across much of the SD plains ahead of the cold front, with 70s behind it. RH values will drop into the low- teens to single digits. Due to these conditions, the RFW will continue to be in effect through 9 PM MDT for much of the SD plains. Friday will be similar to Thursday, with comparable temperatures, RHs, and gusty winds over northwest SD. However, the stronger winds are not expected to overlap with the lowest RHs, so a RFW currently appears unlikely. Cooler temperatures and increased RHs will return by the end of the weekend and into the beginning of next week with increased chances for precipitation.

DISCUSSION

(This Afternoon Through Tuesday) Issued at 1121 AM MDT Wed May 13 2026

Western CONUS ridge will remain in place most of this week, supporting warm and dry weather. Ridge topping impulses will support weak cool fronts at times, with little to no precip with each system. Breezy southeast winds have developed across western SD in response to the advancing Pac NW upper trough. Associated frontside impulse will shift east into NE WY later this afternoon and evening. Sufficient LL moisture should be in place for isolated high based showers/TS. If convection does develop, gusty winds would be expected per inverted-V profiles. Any convection will shift NE overnight in very isolated fashion. Retained low pops for this. Sfc trough will shift through the FA tonight into Thur morning, supporting gusty NW winds. Breezy winds can expected Thur, esp over NW SD where adv level winds are expected with gusts over 50 mph at times. Issued a wind adv for this. Breezy NW winds will continue into Friday as another weak impulse advects through westerly flow on the south side of the deeper southern Canadian upper trough. Deeper upper trough will move into the Rockies this weekend, leading to much cooler temps by Sunday, as well as slightly better chances for showers into early next week. However, the bulk of moisture stays east of the FA, with more isolated to scattered activity expected in the FA. Expect highs in the 50s and 60s most places Monday and Tues, with some 40s in the west Monday, before things start to warm back up Wed. Some frost will also be possible in this period, esp across northeast WY.

AVIATION

(For the 06Z TAFS Through 06Z Thursday Night) Issued At 1030 PM MDT Wed May 13 2026

VFR conditions are expected through the TAF period. Higher based isolated showers will continue crossing northeastern Wyoming and far southwestern SD over the next few hours...and perhaps toward central SD later tonight. Gusts as high as 45kt will be possible in these showers, and most of the precipitation will not reach the ground.

A cold front will cross the area after 06z, bringing gusty NW winds behind it. These breezy winds will continue through Thursday, with afternoon gusts to 45 kts possible across far NW SD.

FIRE WEATHER

Issued At 1121 AM MDT Wed May 13 2026

Warm, dry and, windy conds with receptive fuels will continue to support critical to near critical conds to most of western SD through the end of the week. A red flag warning remains in effect through Thur, with a long duration of critical fire weather conditions expected. Breezy SE winds today ahead of a trough of low pressure. Very dry conds, with RH's expected to fall to as low as 10 percent both today and Thur afternoon (Friday as well). The trough will move through this evening and support gusty NW winds, with poor overnight recovery. Gusty NW winds will continue Thur with continued very dry profiles. Dry and breezy through Sat. The red flag warning will most likely need extended across southwest SD Friday as critical fire weather conditions are forecast. Cooler with shower chances early next week, leading to a break in fire weather concerns although the best chance for wetting rains will be east of the area.